A virtual machine (VM) is a software implementation on a computer system that emulates the functionality of a physical or host computer. VM's can operate within a virtualization layer that runs on top of a client or server operating system. The host computer can operate multiple VM's that function independently of each other and can run their own operating system or programs. Although the VM and host share common hardware resources the VM operates as its own computer with a virtual processor and memory that enable the VM to function as a separate computer system. The host computer can be configured to share resources between multiple VMs to enable concurrent operations of multiple VMs.
VMs can be replicated or migrated between multiple host computers or servers to optimize hardware utilization or for backups, disaster recovery, and network maintenance. VM configuration and operations logs can be replicated or migrated in their entirety or in real time or near real time to facilitate the seamless replication or migration between host computers. However, VM replication or migration can become open ended and not terminate within a reasonable time if not properly managed.